This project is concerned with the development, implementation and application of methods, algorithms and computing systems for the quantitative analysis of the electrophysiologic functioning of the human brain as recorded from the scalp. Results of these efforts are being applied to clinical and research problems in the diagnosis and treatment of the seizure disorders, the assessment of blood serum level of active metabolites of psychotropic medication, the assessment of impaired function in elderly persons, and in general with the assessment of the relationships between normal and impaired electrophysiologic function and behavior. An integrated, interactive computing system, ADIEEG, performs primary spectral and time domain analyses and display, heuristic and statistical feature extraction, and piecewise quadratic pattern classification on up to 16 EEG channels, on-line in a single dedicated minicomputer. Novel aspects of this system include automatic rejection of artifact and data contaminated by drowsiness, detection of transient paroxysmal activity associated with the seizure disorders, simple clustering methods for data subset selection and combination, and nonstationary spectral analyses. Work also continues on the problem of reducing irrelevant intra- and inter-subject variation in electrophysiologic measurements by devising an adequate set of behavioral conditions for clinically assessing the status of cortical function. BIBLIOGRAPHIC REFERENCES: Gevins, A.S., Zeitlin, G.M., Ancoli, S., and Yeager, C.L. Computer rejection of EEG Artifact, Part II: Contamination by Drowsiness. Electroenceph. Clin. Neurophysiol., 1977, in press. Gevins, A.S. On-line computing in clinical neurophysiology. Proc. Assoc. Advancement of Medical Inst., March, 1977.